Yes, the driver is required. XPII is compatible with MKII, and XPII and MKII share the same driver provided by AVR Studio. After installed the software, you can find the corresponding MKII device under the option Jungo in the Device Manager.

Question:

Does this downloader support Win8 OS?

Answer:

Yes, it supports, but you should install the latest version of software provide by Atmel Atmel Studio.